SOCKS

SOCKS and SOCKS proxies

The SOCKS proxy is working as of release 0.7.1. SOCKS 4/4a/5 are supported.
Enable SOCKS by creating a SOCKS client tunnel in i2ptunnel.
Both shared-clients and non-shared are supported.
There is no SOCKS outproxy so it is of limited use.

Many applications leak sensitive
information that could identify you on the Internet. I2P only filters
connection data, but if the program you intend to run sends this
information as content, I2P has no way to protect your anonymity. For
example, some mail applications will send the IP address of the machine
they are running on to a mail server. There is no way for I2P to filter
this, thus using I2P to 'socksify' existing applications is possible, but
extremely dangerous.

And quoting from a 2005 email:

... there is a reason why human and
others have both built and abandoned the SOCKS proxies. Forwarding
arbitrary traffic is just plain unsafe, and it behooves us as
developers of anonymity and security software to have the safety of
our end users foremost in our minds.

Hoping that we can simply strap an arbitrary client on top of I2P
without auditing both its behavior and its exposed protocols for
security and anonymity is naive. Pretty much *every* application
and protocol violates anonymity, unless it was designed for it
specifically, and even then, most of those do too. That's the
reality. End users are better served with systems designed for
anonymity and security. Modifying existing systems to work in
anonymous environments is no small feat, orders of magnitude more
work that simply using the existing I2P APIs.

The SOCKS proxy
supports standard addressbook names, but not Base64 destinations.
Base32 hashes should work as of release 0.7.
It supports outgoing connections only, i.e. an I2PTunnel Client.
UDP support is stubbed out but not working yet.
Outproxy selection by port number is stubbed out.